Specific criteria for implantable cardioverter defibrillator (ICD) implementation as a primary preventative treatment for patients who suffer from ventricular fibrillation and tachycardia and are at risk for sudden cardiac death is associated with clinical guidelines. Yet there is not a definitive set of criteria within guidelines that address patients who are replacing their ICD generators, and there are no measures to ensure that the device is still needed as a continuing form of treatment.

Additional Resources 2012 ACCF/AHA/HRS Focused Update Incorporated Into the ACCF/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities ACCF/HRS/AHA/ASE/HFSA/ SCAI/SCCT/SCMR 2013 AUC for ICDs and CRT Cardiac Rhythm Management Clinical Community ICD Registry CardioSmart for Your Patients: About ICDs

In a study published April 9 in the  Journal of the American College of Cardiology, a team led by Vinay Kini, MD, Hospital of the University of Pennsylvania, Philadelphia, PA, sought to determine factors when looking at ICD generator replacement, and found that a quarter of patients who receive ICDs for primary prevention may no longer meet guideline-driven indications for continued ICD use when their original batteries reached elective replacement or end-of-life indicators.

The study was conducted through a retrospective chart review of 231 patients at two locations undergoing replacement of an ICD at the time of generator replacement. The indications for continued ICD therapy at time of generator replacement included left ventricular ejection fraction (LVEF) < 35 percent or receipt of appropriate device therapy. The results showed that 59 patients (26 percent) no longer met the guidelines for an ICD at time of generator replacement. An additional 79 patients (34 percent) had not received any appropriate ICD therapies and had not undergone reassessment of their LVEF. Patients with an initial LVEF of 30-35 percent were less likely to meet the guidelines for ICD therapy at time of replacement (OR 0.52, 95 percent CI 0.30-0.88; p=0.01). Patients without ICD indications subsequently received appropriate ICD therapies at a significantly lower rate than patients who did (2.8 percent vs. 10.7 percent annually, p < .001). Further, the authors found that if ICD generator explants were performed instead of replacements in the patients that no longer meet the ICD guidelines, the cost savings would be $1.6 million.

The authors conclude that approximately 25 percent of patients who receive primary prevention ICDs may no longer meet the guidelines for ICD use at time of generator replacement and these patients can receive subsequent ICD therapies at a significantly lower rate. These results bring to light a gap in providing the appropriate continuing care to ICD patients whether it is replacing the ICD generator or using alternative ICD therapies. They note that there is an opportunity for institutions to cut down costs and readmissions while still keeping the patients' needs at the forefront.

In a corresponding editorial comment, N. A. Mark Estes, III, MD, FACC, writes that "Kini and his colleagues have brought an important clinical issue to the forefront. Their data do support the case to perform ICD explants instead of generator replacement in patients with no appropriate therapies and significant improvement of LVEF. However, it is evident that there are many gaps in current knowledge related to the optimal ICD replacement strategy." He adds that moving forward, "defining the optimal approach will require clinical trials and registries to bridge the many gaps in our current knowledge."

Keywords: Registries, Ventricular Fibrillation, Stroke Volume, Cost Savings, Death, Sudden, Cardiac, Defibrillators, Implantable, Primary Prevention, Tachycardia